1. Field of the Invention
The present invention relates to a TAB (tape automated bonding) tester for recognizing a state of the TAB by an image before it is measured or after it is measured and classified.
2. Prior Art
An arrangement of a prior art TAB tester will be described with reference to FIG. 4. The TAB tester comprises a supply reel 2 on which a tape carrier 11 is mounted or wound, a pusher 4 for pushing down the tape carrier 11 downward for permitting the tape carrier 11 to contact an IC tester so as to conduct the TAB so that the TAB is subjected to an electric test by the IC tester, sprockets 5A and 5B which are synchronously rotated for transferring the tape carrier 11, a group of detectors 12 for detecting the TAB to judge that it is a reader tape or the TAB to be tested, a punch unit 6 for punching the TAB of the tape carrier 11 depending on the result of electric test of the TAB by the IC tester to form an identification hole or punching an IC chip, a group of detectors 13 for detecting data and an accommodating or winding reel 3 for accommodating or winding the tape cartier 11 which was subjected to the electric test.
There are also provided an image camera 7A for taking an image of the TAB with the help of light emitted from a light source 8A, an image processing unit 9 for receiving and processing the image taken by the image camera 7A to thereby convert the image into an image data, a control unit 10 for receiving the image data from the image processing unit 9 and controlling the position of the TAB when the TAB is measured.
The group of detectors 12 comprise three detectors and they are disposed upstream relative to the sprocket 5A. The group of detectors 13 comprise three detectors and they are disposed downstream relative to the sprocket 5A. The arrangement of the group of detectors 12 is the same as that of the group of detectors 13.
FIG. 5 is an arrangement of the group of detectors 12. A detector body 20 is formed of a U-shape and comprises a light emitter 21 at the first tip end thereof and a light receiver 22 at the second tip end thereof at the portion confronting the light emitter 21.
In FIG. 5, the tape carrier 11 travels on the groove defined in the detector body 20 so as to detect the TAB. The detector body 20 is held by a moving body 23 and moves forward and backward relative to the traveling direction of the tape carrier 11 in the direction to traverse the traveling direction. The moving body 23 moves in parallel with the traveling direction of the tape carrier 11. The groups of the detectors 12 and 13 have the arrangements as illustrated in FIG. 5 and the detecting positions thereof are adjusted before the TAB tester operates.
The group of the detectors 12 comprises detectors 12A, 12B and 12C which are disposed on the tape carrier 11 as illustrated in FIG. 6. In FIG. 6, the detector 12A is adjusted to be positioned at the portion where the detecting light shields one of test pads 11A. The detector 12B is adjusted to be positioned at the portion where the detecting light shields the IC chip 11B. The detector 12C is adjusted to be positioned at the portion where the detecting light transmits a marked hole 11C. The detector 12A confirms that the tape cartier 11 is a reader tape or the TAB to be tested based on the presence of the detecting light. The detector 12B confirms the presence or nonpresence of the IC chip 11B based on the presence or the nonpresence of the detecting light, thereby judging the necessity of the measurement of the TAB. The detector 12C confirms the presence or nonpresence of the marked hole 11C based on the presence or nonpresence of the detecting light and also confirms that the TAB has been already measured and classified.
Depending on various testing steps of the TAB, the marked hole 11C on the TAB is used for testing again the TAB on which the marked hole 11C is punched or punching an identification hole by the punch unit 6 showing better or poor goods after the TAB is tested.
An operation of the conventional TAB tester as shown in FIG. 4 will be described hereinafter.
Data of TAB detected by the group of detectors 12 is stored in the control unit 10. When the detected TAB is moved under the pusher 4, the control unit 10 reads the data of TAB and issues instruction of necessity of the measurement of the TAB by the IC tester.
The TAB which is instructed to be measured by the control unit 10 is positioned to an electrode, not shown, connected to the IC tester and subjected to an electric test. After the TAB was subjected to the electric test, it moves to the punch unit 6. The punch unit 6 punches the identification marked hole 11C or punches the IC chip 11B.
Successively, when the TAB moves to the group of detectors 13, the data stored in the group of detectors 12 and the result of classification by the punch unit 6 are compared and collated with the data detected by the group of detectors 13. If the result of comparison and collation shows that both the data are agreed with each other, the tape carrier 11 is unwound on or accommodated in the accommodating reel 3. When the group of detectors 13 detect the tape carrier 11 which was completely wound, they judge that the tape carrier 11 is the tape end and a series of operations complete.
Depending on various testing steps, the TAB is tested by a burn-in tester in the step before it is tested by the TAB tester in FIG. 4. When the TAB is tested by the burn-in tester, the tape carrier 11 is cut in a given length. Accordingly, in the step where the TAB is tested by the TAB tester, the tape carrier 11 is moved while a TAB 11D and a TAB 11E are connected to each other by an adhesive tape as shown in FIG. 6.
In the TAB tester in FIG. 4, if there are joints on the tape carrier 11 as shown in FIG. 6, there is a possibility that the TAB is erroneously detected since the TAB is not transferred accurately to the setting position of each sensor unit. In addition, there is a possibility that the TAB is not measured since the detecting means 1 of FIG. 6 judges that there is no IC chip because the IC chip has been recently miniaturized in the width of e.g. about 1 mm.